February 1-5, 2011 Arctic Blast/Winter Storm Discussion

[srainhoutx]

Welcome to all our new folks. The 18Z NAM suggests a a bit more widespread event. Temps aloft are colder and that model suggests some mesoscale banding across much of SE TX...

[jeff]

Jeff, what's you best estimate as to start time for event tomorrow? Obviously has huge implications for school/work/travel issues. Especially for those that still think event will hold off and begin Thursday night!!

Probably virga on the radar by noon with precip. starting to reach the ground in the 300-400pm time frame (sooner around Matagorda Bay).

[kwoodwx]

Any thoughts on snow for the Kingwood/Humble area?

[harpman]

Reports coming in all over s.e. La. of light sleet and snow!

[AggieBuckeye]

Jeff:

Thanks so much for stopping by. Is it possible to add a few to your email list? I have a few wanting to be added.

[jeff]

Any thoughts on snow for the Kingwood/Humble area?

2-4" with locally higher amounts

[jdman]

don't think I would want to be participating in the nightmare that could be Houston "rush hour" tomorrow evening. I'll take my little desolate corner of NW Montgomery County any day and especially tomorrow!!!!!

[Texashawk]

Jeff,

I'd like to be added too as well. Your e-mails are clear, informative, and generally free of excessive hyperbole.

[Ptarmigan]

If we have frozen rain, it will be a real mess for sure. Whatever the outcome is, this winter weather event will be memorable.

[MRG93415]

Jeff,

I'd like to be added too as well. Your e-mails are clear, informative, and generally free of excessive hyperbole.

Jeff, I would like to be added as well if I could....Ditto to the above post.

[clute28]

Jeff how much ice/sleet would we get before it changed over to snow if it did at all..in Clute

[jeff]

Jeff how much ice/sleet would we get before it changed over to snow if it did at all..in Clute

.1-.25 maybe .5, but I still think more sleet/snow than ZR.

[srainhoutx]

I'm on my phone, but if someone has the most recent e-mail from Jeff, a lot of questions could be cleared up...

[redneckweather]

29.3 and holding at my house.

One quck question Jeff. I'm guessing the Montgomery/Conroe area could be in for 2-4 inches with possible higher amounts?

[jeff]

29.3 and holding at my house.

One quck question Jeff. I'm guessing the Montgomery/Conroe area could be in for 2-4 inches with possible higher amounts?

Sounds good to me.

[wxman57]

Would also note that NAM has been showing convective precip on its last few runs...Could be some 1-2 inche per hour rates under that.

Jeff, did you notice that the 18Z NAM has warmer air aloft? Possibly indicating a longer period of freezing rain/sleet (note: this is for Downtown Houston):

[updraft]

Just to elaborate a little on wxman's info on electricity issues .... just got out of a state-wide conference call and here's the latest info:

As wxman stated, problems today and especially this morning were due to electricity demand - but coupled with power generation plant issues. Anytime we have an extended period of below freezing temps, generating plants fight a constant battle to keep aux systems running (those that support the main unit producing electricity). Typical problems are air supply to instrumentation and the obvious water lines supporting operations. Wholesale electricity prices spiked to $3,000 per MW hr. this morning and currently struggles to dip below $100 per MW hr. (Compared to typical zone prices of $16 per MW hr.) Currently, with regards to the Houston zone, all generating plants are stable and although several units are down, work is underway to restore soon. However, all are currently and will continue to experience equipment issues related to freezing.

Ercot (controls and operates the Texas power grid) has mandated all power generating plants keep their units running at all costs until 11am tomorrow (which will likely be extended). This sounds like an obvious protocol, but let me assure you, this is a serious issue as there is just not enough power being generated for the demand. Generating plants are required to ask permission to shutdown for any reason during this protocol. Ercot has stated the grid is stable at the moment, but expect the situation to become serious again in the 4 - 6pm time frame as peak demand starts. Large-scale rolling blackouts will continue and likely increase during this period.

From a power plant point of view, I don't see this event as bad as '89 .... yet. But for equipment that runs on air and water, it can have a domino effect once something starts to fail - so it will be "dicey" (or is that icy?) over the next few days. It can change from bad to worse very quickly.

The tendency during cold periods such as these is to crank up the heat when you come in from the cold.... use discretion when you turn up the thermostat and especially when you reach for the light switch. I urge everyone to conserve electricity where possible and spend the next few nights/days bundled in a blanket with a romantic candle light dinner. And please, for those that still have Christmas lights up (you know who you are), make sure they don't turn on for the next few days

[ticka1]

latest email from Jeff Lindner:

***Winter Storm Watch issued for all of SE TX, all of the coastal bend, and S Texas***



***Potentially historic winter storm event shaping up for Texas***



Significant accumulations of ice now likely resulting in downed power lines and trees limbs across the coastal sections of TX with heavy snow across inland locations. Ice accumulations may approach 1/4th to ½ of an inch which is well into the local warning criteria for winter storm/ice storm watches/warnings. Widespread power disruptions/outages appear possible.



4.4 inch snowfall for KIAH in 1960 may be challenged with this event (this is the second highest snow total for Houston on record). The highest is 20 inches on Feb 14, 1895 and I think that record will stand!



Discussion:

Models are not handling the rapid advection of moisture into the region today as noted by the increasing cloud cover. Water vapor shows an impressive plume of Pacific moisture aimed right at the region and this will increase with time. Large scale upper low over continues to dig into the great basin and will begin the eject eastward Thursday. Appears models forecasting worst case QPF amounts are in fact going to be the correct route to follow and will bump all totals while adding heavy ice accumulations to parts of Harris, Galveston, Brazoria, Matagorda, Chambers, Calhoun, and Victoria counties.



Will attempt to resolve the P-type changes that we are going to face, but it is really a guessing game as to when P-types change and how this affects accumulations. Models have intensified the warm nose forecast to back toward the coast while keepings surface temperatures well below freezing which now brings the threat of heavy freezing rain/sleet to the SE 1/3rd of the area and snow/heavy snow elsewhere. Other item will be to onset precipitation between noon and 300pm Thursday and linger it until early afternoon Friday giving the area an extended period of falling precipitation. Impressive 50kt moisture advection above this cold dome is forecast on Thursday afternoon…so what does fall could be on the heavy side.



So here we go as my best shot right now on P-types and accumulations:



SE of a line from Alice to Victoria to Bay City to Angleton to downtown Houston to Liberty:

Freezing rain/sleet mix starting Thursday afternoon and continuing into Thursday night. Warm nose may deepen enough to remove sleet and keep all freezing rain. Friday morning colder air sweeps in a change over to snow. Ice accumulations of .10-.5 of an inch on all surface will likely produce downed trees and power lines. I am not sure the models have that warm nose correct, and if they do not if could be all snow for the coast.



SE of a line from Livingston to Columbus to San Antonio:

Sleet starting Thursday afternoon changing to snow. This area appears to lie in the most favorable lift and moisture area (roughly along US 59) for the most impressive accumulations. Expect all snow Thursday night and Friday. Meso scale bands will produce very heavy snowfall of 1-2” per hour. Will go with accumulations of sleet of less than 1 inch and snow fall accumulations of 3-5 inches area wide with isolated totals upwards of 6-8 inches under the meso bands.



For the rest of the area:

Snow will onset for the entire event. Accumulations of 1-3 inches are likely with isolated totals of 4-5 inches.



Actions:

HCTRA and TXDOT are applying anti-icing agent to area freeways/bridges and overpasses at this time across the entire region

Tracks are being equipped with spreaders and loaded with sand to spread on area freeways

Harris County EOC has moved to Level 3 activation



Residents should prepare today for potential widespread power outages, down tree limbs and power lines, and extremely dangerous travel conditions.



Hazards:



Travel:

Conditions will rapidly go downhill with the onset of the precipitation. Very cold ground temperatures/road temperatures are already in place suggesting that what falls will freeze/accumulate on impact. Surface roads will be in just as bad of shape as bridges and overpasses given the very cold ground. Expect travel will be nearly impossible by Friday morning on all major freeways and surface streets. Sanding operations will only have modest success due to precipitation intensity and widespread nature of the event and road crews will likely be overwhelmed quickly.



Power/Vegetation:

Now that freezing rain/icing is becoming a larger threat along the coast significant impacts to trees and power line are possible. Weight of glazed ice on tree limbs and power lines may result in extensive damage and widespread power outages. Texas power grid is already under tremendous strain due to frozen natural gas supply lines and this will potentially add more strain and damage to the network. Power conservation is strongly encouraged to help maintain the stability of the entire power grid and ERCOT has ordered rotating blackouts to help reduce the strain on the system. Damage by ice to the actual power infrastructure is possible…and restoration will not be quick.



Aviation:

Big trouble on this aspect as aircraft will require extensive de-icing of control surfaces and runways ice/snow removal. Given the expected intensity of the falling precipitation and very cold surface temperatures, it will be hard for ground crews to keep up and expect significant delays and cancellations at both major Houston airports.



Will try and get the next update out by 430/500pm with updates on accumulations.



Winter Storm/Ice Storm Warnings will be required later tonight if not sooner.

[Ptarmigan]

Just to elaborate a little on wxman's info on electricity issues .... just got out of a state-wide conference call and here's the latest info:

As wxman stated, problems today and especially this morning were due to electricity demand - but coupled with power generation plant issues. Anytime we have an extended period of below freezing temps, generating plants fight a constant battle to keep aux systems running (those that support the main unit producing electricity). Typical problems are air supply to instrumentation and the obvious water lines supporting operations. Wholesale electricity prices spiked to $3,000 per MW hr. this morning and currently struggles to dip below $100 per MW hr. (Compared to typical zone prices of $16 per MW hr.) Currently, with regards to the Houston zone, all generating plants are stable and although several units are down, work is underway to restore soon. However, all are currently and will continue to experience equipment issues related to freezing.

Ercot (controls and operates the Texas power grid) has mandated all power generating plants keep there units running at all costs until 11am tomorrow (which will likely be extended). This sounds like an obvious protocol, but let me assure you, this is a serious issue as there is just not enough power being generated for the demand. Generating plants are required to ask permission to shutdown for any reason during this protocol. Ercot has stated the grid is stable at the moment, but expect the situation to become serious again in the 4 - 6pm time frame as peak demand starts. Large-scale rolling blackouts will continue and likely increase during this period.

From a power plant point of view, I don't see this event as bad as '89 .... yet. But for equipment that runs on air and water, it can have a domino effect once something starts to fail - so it will be "dicie" (or is that icy?) over the next few days. It can change from bad to worse very quickly.

The tendency during cold periods such as these is to crank up the heat when you come in from the cold.... use discretion when you turn up the thermostat and especially when you reach for the light switch. I urge everyone to conserve electricity where possible and spend the next few nights/days bundled in a blanket with a romantic candle light dinner. And please, for those that still have Christmas lights up (you know who you are), make sure they don't turn on for the next few days

Thanks for the heads up! I still don't understand why anyone would light up their Christmas lights after January 6th. Reminds me of a King of the Hill episode, where Bill Dauterive had Christmas decorations into March.

The December 1989 Freeze happened around Christmas and many were out of town when it happened.

[Ptarmigan]

How do I get to be on Jeff's e-mail list and get updates from him?